<script setup>
import { ref } from 'vue';
import ChildTwo from './components/ChildTwo.vue';
const car = ref('自行车')
const changeCarCb = (newCar) => {
  car.value = newCar
}
</script>

<template>
<div>
  父组件 --- {{ car }}
  <ChildTwo :car="car" :change-car-cb="changeCarCb" @change-car="car=$event"></ChildTwo>
</div>
</template>